离子推力器电子反流的理论预测与试验测量

详细信息

THEORY AND EXPERIMENT OF BACK-STREAMING FOR ION THRUSTER

Science and Technology on Vacuum & Cryogenic Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China

摘要: 对离子推力器来说,加速栅的作用是提供一个负的电势壁垒,阻止下游的电子反流到放电室内部。反流电子流不仅会导致推力器能量损失,严重的甚至会导致推力器无法工作。电子反流阈值是由加速栅孔内的鞍点电势所决定的,而决定鞍点电势的因素有屏栅和加速栅的电势,屏栅和加速栅的几何结构,子离子束流的大小。推导了鞍点电热公式,采用监测屏栅电流的变化的方法,测量出反流阈值,并与理论计算值相比较。
- 电推进 ;
- 电子反流 ;
- 鞍点电势
Abstract: For ion thruster,the accel grid can produce a potential barrier to stop neutralizer electrons from flowing back into the discharge chamber.The backstreaming electron current is not only a parasitic power loss,but it can damage the thruster.The back-streaming limit is determined by the "saddle-point" voltage and the factors related to the "saddle-point" including the voltage of screen grid and accelerator grid;the structure of grids;the beamlet current.In general,there are two methods to measure the back-streaming limit.This paper choose the method to monitor the increase in the screen power supply current as the magnitude of the accelerator grid voltage is decreased.
- ion thruster /
- back-streaming /
- saddle-point voltage